Draft: Tezlink/RPC : Add get storage RPC to Tezlink

What

Expose the storage RPC for smart contracts in the Tezlink service.

Why

This RPC enables users and external tooling to query a contract's current storage state directly via Tezlink. It is essential for smart contract introspection and tooling interoperability.

How

• Imported the storage RPC from the protocol plugin contract services.
• Registered it under the block services in tezos_services.ml.
• Implemented storage in the Tezlink backend using durable storage reads.
• Added the Path.storage helper and used it to locate contract storage in the durable tree.
• Edited Octez-client contract_storage function so that endpoint can be edited.
• Wrote a Tezt test test_tezlink_storage to verify retrieval of the storage for bootstrap1.

Manually testing the MR

Run the test suite and ensure test_tezlink_storage passes:

make octez-client && make octez-evm-node && dune exec etherlink/tezt/tests/main.exe -- tezlink storage

You can also test manually using curl at this path on the node :
curl http://localhost:<port>/tezlink/chains/main/blocks/head/context/contracts/<contract>/storage